Field of the Invention
The disclosure relates to a power charging method and, more particularly, relates to a charging method and a portable electronic apparatus using the same.
Description of the Related Art
With the development of technology in recent years, various portable electronic apparatus, such as a tablet computer, a person digital assistant, a laptop computers and smart phones, are necessary tools in life.
A battery with large capacity needs long time to be charged up. Thus, to recharge the battery with large capacity in a short time, the charge efficiency must be improved.
In general, the battery is charged up via a pre-charge mode when the electric quantity is low. While the electric quantity of battery achieves a predetermined value, the charge mode is switched to a constant current mode, and then while the voltage of the battery approaches to the full-charge voltage, the charge mode is switched again to a constant voltage charge mode to charge the battery until the battery is fully charged.
Using the constant current mode to charge up a battery is faster than using the constant voltage charge mode, in which the constant current and the constant voltage are determined according to the voltage of the battery. However, the measured voltage of the battery is not reflecting a real voltage of the battery that is caused by the battery inner resistance. Thus general charging control module is switched to the constant voltage mode before the real voltage of the battery achieving to predetermined fully charging voltage, thus the charging velocity of the battery is reduced.